In a conventional fuel injection valve, an injection hole in a housing is opened and closed by reciprocation of a needle to inject fuel in the housing to the outside. For example, Patent Literature 1 describes a fuel injection valve provided with a housing having injection holes with different inner diameters, which are provided according to position of a spark plug.
In the fuel injection valve described in Patent Literature 1, the inner diameter of the injection hole is constant from an inner opening formed in the inner wall of the housing to an outer opening formed in the outer wall of the housing. For this reason, different quantities of fuels flow in the injection holes having different inner diameters per unit time. Thus, fuel may not be reliably atomized in a combustion chamber. Unatomized droplet-like fuel in the fuel injected from the injection hole readily leads to imperfect combustion, possibly increasing the quantity of generated particulate matters.